I am wondering if any of you have seen this type of dammage before.
What was the cause of the dammage.
If the dammage is too severe to run the engine. The Kitty will not be used much.

I expect this is from preignition.

I would start by checking if the injector nozzles are the correct ones and spraying fuel properly and cracking at the correct pressure for that engine. Even if this all checks out ok, then the injection pump lifter settings would be the next step in making sure this doesn't continue.

It would be best to change it out. What is the worst problem it can cause if it fails? Old design 2 piece pistons are known for coming apart anyway. Usually these didn't do a whole lot of additional damage to the engine, but I have a larger engine in a grader which had a piston failure and the rod beat the sleeve and block out before they shut it down. Had to start over with a bare block and rebuild it.

I'm no expert, but if all the pistons look like that I would check to see if it had fuel filters. Water could be a possibility. I have heard from diesel mechanics that water in the fuel will burn a hole right through the piston right under the injector. But like I said, I am no expert.

Ken

I have seen all types of piston damage, and it can be difficult to pin down the precise cause. Caterpillars technical advice is big on doing intensive detective work, and logical analysis of events that led to the damage.

The picture shows piston bowl damage caused by overheating in the combustion chamber. Overheating in the combustion chamber can be caused by the following ..

Blocked intake or exhaust (incoming cool air is not cooling the piston) ..

Fueling problems .. broken down as follows ..

1. Leaking fuel injection nozzle ..
2. Spray jet problem, caused by faulty fuel injector (squirts in a stream, rather than atomises in a spray) ..
3. Incorrect injection timing ..

Overheating (poor condition cooling system) ..

Overloading (excessive lugging at high engine temperatures) ..

Incorrect rack setting ..

You do not have a problem at present, as the piston damage is not yet severe. However, operation with the problem unresolved will result in the damage increasing, resulting in total engine failure.
Some time spent on checking the above, will be time well spent. The old adage about "for want a nail, the ship was lost" is very applicable here.
Finding the cause will not cost a fortune .. but I can assure you that a premature engine failure will ..